Date of Defense:
August 28, 2009
Objectives: To examine cross-sectional and longitudinal associations between socioeconomic status (SES), gender, sports participation and moderate-to-vigorous physical activity (MVPA) in adolescents.
Methods: Project EAT (Eating Among Teens), a population-based longitudinal study followed a socioeconomically and ethnically diverse sample of 1709 adolescents in 1998-1999 (Time 1) and 2003-2004 (Time 2). Mixed model regression analyses were used to examine longitudinal trends in MVPA as a function of SES and previous sports involvement.
Results: For both genders, participation in organized sports and weekly hours of MVPA were positively associated with SES. On average, MVPA decreased between high school and young adulthood for both genders. Adolescents who participated in sports during high school showed a steeper decline in weekly hours of MVPA than their non-sports-participating counterparts. SES had a significant moderating effect on the change in MVPA over time for boys who participated in organized sports, with low SES boys showing a steeper decline in MVPA between time periods than higher SES boys. Although on average, a statistically significant difference in MVPA between previous sports participants and nonparticipants remained at Time 2, for all SES groups and both genders, the gap between hours of MVPA was either overcome or significantly narrowed by young adulthood.
Conclusions: Increased dependence on organized sports for MVPA may be insufficient to meet the needs of youth following high school, especially for low SES youth. Designing physical activity promotions that reach and address the unique needs of lower SES youth and families is a public health priority.